Recently, an ultrasound system has been extensively used in the medical field due to its non-invasive and non-destructive nature. Modern high-performance ultrasound imaging diagnostic systems and techniques are commonly used to produce two- or three-dimensional ultrasound images of internal features of patients. To provide the ultrasound images, the ultrasound system operates in various image modes such as a brightness mode, a Doppler mode, an elastic image mode and the like to acquire ultrasound images for diagnosis.
Generally, the ultrasound system transmits ultrasound signals to a target object and receives echo signals to thereby form an ultrasound image. The transmission and reception of the ultrasound signals may be repeatedly carried out in a sequential manner so that a plurality of ultrasound images may be formed.
The ultrasound system may operate in various modes, e.g., a brightness mode, a Doppler mode, an elasticity mode, a 3-dimensional mode and the like. When the Doppler mode or the elasticity mode is selected, it is preferable that an ultrasound probe for transmission and reception of ultrasound signals is kept at an identical position on a target object to obtain better images in such modes. However, since the surface of a human body is curved and a user's hand may be moved, it may be difficult to keep the ultrasound probe at the fixed position. Thus, image qualities in such modes may be degraded due to the motion of the ultrasound image.